USB HID Support on Pico!

This build still needs external Battery or just the save()?

Just save() this time, but I think you figured that out? :)

can one grab and use the console's serial port on the Espruino side for that so that data sent to the USB modem dev on the host would end up in some serial buffer on the Pico?

Yes, you just need to move the console out the way and then you can do what you want:

LoopbackA.setConsole(); // or you can put it on Serial1 if you want?
USB.on('data',function(d) { ... });

USBTablet

Ok, I'll update the module. Very interesting that a plug in device can crash the UI! :o

As you say, I doubt the clipping/offset is anything Pico-related - the data sent from the Pico obviously doesn't have anything done to it (it works fine on Linux), so I wonder whether your Macs have some kind of 'calibration' that's applied?

Very strange about the keyboard example and the context menu - I actually tried that on a Mac and it worked great.

the physical minimum/maximum value ... don't seem to have any effect

Interesting - so it's just the logical values? To be honest I didn't read it properly and assumed they were X and Y.